Uterine fibroid tumors (also referred to as “uterine fibroids” or “leiomyomas”) are non-cancerous tumors of the uterine wall that occur in 20 to 50% of women, and have an astonishingly high accumulative incidence. Current studies demonstrate that by age 50, 70-80% of women have developed uterine fibroids, with higher incidence in African-American women, who commonly develop fibroids earlier than other racial groups. A significant number of those with uterine fibroids suffer from debilitating pelvic pain, heavy and prolonged bleeding (which may lead to anemia and iron deficiency), bowel and bladder dysfunction and infertility. Uterine fibroids also cause symptoms such as low back pain, urinary frequency and urgency, pain during intercourse (dyspareunia), and negative impact on fertility. They are associated with high morbidity from uterine bleeding and pain along with health care costs estimated to be between $2.1 and $34.4 billion annually in the United States alone. Therefore, uterine fibroids have a significant impact on the health and well-being of reproductive age women and on the economy. After menopause, generally, fibroids shrink and only rarely cause problematic symptoms.
The etiology of this disease remains unknown, therefore there are no methods of preventing uterine fibroids. Several treatments are available, but hysterectomy is the only treatment which can permanently eliminate fibroids. The majority of the hysterectomies performed in the United States each year are due to uterine fibroids. It is obvious, but rarely stated in the literature, that hysterectomies lead to irrevocable loss of fertility. This invasive surgery also has a high cost, financially, socially and otherwise. It is associated with lengthy recovery times, potential for sometimes severe postoperative complications, and physical discomfort. Thus, this solution is far from ideal.
Other surgical methods such as myomectomy (surgical removal of the fibroid tissue leaving the remainder of the uterus intact) is commonly used, but may not be suitable in cases where the fibroids are too large or too numerous to leave enough normal tissue behind. Further, the fibroids often recur. In addition, about three-quarters of myomectomy surgeries are open surgeries involving an abdominal incision. Therefore, this method also is associated with complications, discomfort, long recovery, and potentially loss of fertility as well. Myolysis and cryomyolysis, in which uterine fibroids are burned or frozen via laparoscopic surgery, can be used to cause the fibroids to shrink and die over time. However, multiple punctures of the fibroids are needed to treat the entire tumor, and the treatment may cause adhesions post-surgery. MRI guided focused ultrasound also is used in the treatment of uterine fibroids, but this procedure is very expensive, and does not permanently eliminate the fibroids. Uterine artery embolization, during which a catheter is inserted into a femoral artery and guided to a uterine fibroid artery for injection of small particles into the fibroid artery, blocks the supply of blood, resulting in death of the fibroid tissue. Although this procedure is less invasive than traditional surgery, post-surgical pain is a frequent problem. In addition, this therapy, like hysterectomy, is considered a standard treatment for women with no desire for future fertility. Alternatively, MRgFUS provides noninvasive fibroid-specific therapy utilizing high-intensity ultrasonography through the abdominal wall to cause coagulative necrosis in specific fibroids. Guidance and thermal monitoring is provided by dynamic real-time magnetic resonance imaging. The surgical procedures to destroy uterine fibroids while preserving the uterus also have major drawbacks and often are not completely successful, due to re-growth of the fibroid tumors.
Non-surgical, pharmaceutical-based medical therapies are available. Fibroids often are treated by medications aimed at treating the symptoms rather than the fibroid tumors themselves. In the early stages, physicians employ a “wait-and-see” approach, with no treatment or symptomatic treatment until the condition impacts the ability of the patient to function in normal life. Most fibroids are not treated unless they are causing symptoms. However, even in the absence of hysterectomy, fibroids, particularly subserosal fibroids, also can lead to infertility.
The pharmacotherapies which are aimed at shrinking fibroid tumors or preventing increase in size have been disappointing and often have significant side effects. Drugs have been studied and sometimes are effective at shrinking uterine fibroids, but many of these non-surgical therapies have been associated with systemic side effects and therefore have not been approved for clinical use. For example, selective progesterone receptor modulators (SPRM) have not been approved by the FDA due to their effects on the endometrium. Only one drug has been approved for use to shrink uterine fibroids: leuprolide acetate. This drug is used as a short-term treatment which suppresses ovarian function (and therefore causes significant menopausal side effects), shrinking fibroids prior to surgery. Other medical therapies have been suggested in the recent past such as selective estrogen receptor modulators (SERM), but clinical trial results have been disappointing.
Current treatment options for uterine fibroids are inadequate. Hence, there is a continuing need in the art for alternative therapies for the treatment of uterine fibroids which are not open procedures and which preserve the patient's uterus. In particular, because treatment of uterine fibroids costs billions of health care dollars each year, and yet this condition remains a significant problem, there is a need for treatment methods that reduce or eliminate symptoms, provide relief without highly invasive procedures, and which preserve fertility.